Rotator for ship logs



1930. J. WALKER ROTATOR FOR SHIP LOGS Filed Dec. 7, 1928 07/6 men JT/WR/VE/ Patented Aug. 12, 1930 UNITED STATES PATENT, o Fl'cE JEFFERY WALKER, or nin vrrnens'm, ENGLAND ROTATOR FOB SHIPLOGS.

Application filed December 7, 1928, Serial No. 324,547, and mu Britain man as, 1928.

This invention relates to rotators for shiplogs and it has for its object to prevent damage to a rotator especially when streamed amidships and when being hauled inboard after use; the invention also being applicable to rotators which are streamed astern of cruiser-sterned vessels.

The usual construction of ship-log rotator embodies a mainly cylindrical body from which project a number, usually four, of vanes set at such an angle as to cause the body to rotate as it is drawn through the water by the movement of the ship, the line, at the outer end of which the rotator is attached, being trailed from a boom projecting from the ships side.

When a rotator is being hauled inboard it is often a matter of difliculty to prevent it from striking the hull of the ship on being drawn close thereto, either by a tripping line or by a grappling iron on a rope heaved into the water from the deck in order to engage the rotator line, and the result is that the rotator is liable to be damaged and will not function properly until repaired.

The actual damage is usually sustained when a vane strikes the hull with a lateral blow, which generally occurs directly after Cit the rotator arrives alongside, and, assuming a vertical position as it is withdrawn from the water, touches the hull relatively lightly, and is so rotated by the impact that the side of the vane next adjacent to that which first touched the hull is brought into violent contact therewith (partly owing to the weight of the rotator) and is bent or perhaps broken off short.

According to this invention, a rotator for a ship log is constructed with some propelling vanes of reduced size whereby to serve as bumpers or fenders to receive any heavy blow against the ships side occasionedby the spinning of the rotator while being hauled inboard.

One constructional embodiment of the invention is illustrated by way of example in the accompanying drawings, in which Figure 1 is a plan view and Figure 2 is a front end view.

The rotator body A is constructed with two normal propelling vanes B, B, diametri cally opposite one another, and also with two reduced vanes or equivalent bumpers C, C, intermediately thereof and projecting outwardly from the rotator body A considerably less than said vanes B,.B.

Each of said reduced vanes or equivalent bumpers or fenders C, C, projects such a distance from the cylindrical body A of the rotator that when the rotator is spun by the first contact with the hull of the vessel from which it is streamed, that reduced vane C which succeeds the vane B first touching the hull is brought into contact with the hull and receives the heavy blow. due to the spinning of the rotator, or, in other words, the reduced vanes C are so dimensioned that the two normal propelling vanes B cannot strike the hull in succession as the rotator spins on withdrawal from the water.

The aforesaid reduced vanes C may be of any appropriate configuration, and are preferably miniature replicas of the normal vanes B so as to function to some extent as propelling vanes when the rotator is in'the water and operating the log.

While the above described invention relates more especially to logs fitted alongside a ship, it is also applicable tologs towed astern, in which position, however, there is less danger of damage to the rotator.

What I claim is z- A 1. A rotator for a ship log comprising, a generally cylindrical body, a plurality of propeller vanes projecting outwardly from said body, and a plurality of reduced vanes located between said propeller vanes to serve as bumper members.

2. A rotator for a ship log comprising, a generally cylindrical body, a plurality of curved propeller vanes projecting radially from said body, and a plurality of reduced vanes each located between adjacent propeller vanes to serve as bumper members.

i 3. A rotator for a ship log comprising, a generally cylindrical body, a plurality of curved propeller vanes projecting outwardly from and longitudinally of said body, and a plurality of reduced vanes located longitudinally of said body between said propeller vanes to serve as bumper members.

4. A rotator for a ship log, comprising a generally cylindrical body, a plurality of 5 curved propeller vanes progeotinigutwardly 0 said from and longitudinally dy, and a.

pluralit of reduced vanes each located longitudin y i. the dissent propeller vanes 1y of said bum 1V5 sai serveas bum members.

5. A rotator for a s ip log comprising a generally cylindriogl 0 urality of curved pro ller veins disposed ongitudmalsaid 6. A router cylindrical body, a

, and a plurality-of rue-like embers arranged longitudinally of fire p'i-o lie! vanes.

for a ship 9g, comprising a lurality of propeller vanes disposed elically u ion aider dy;

and d. plurality of vane-1i e 7 2o bumier members arranged longitudinally of oily parallel with the axis thereof, each of said vane-like bumper members being 10- between adjacent pro ller vanes and each vane-like-bumper mem r being minia- 25 fillrereplica of one of said curved propeller Win s. 1

'' "In fie'sfiknony whereof he afixes his signai p JEFFERY WALKER. 

